When constructing a home or a facility, it is well known to provide garage doors which utilize a motor to provide opening and closing movements of the door. Motors may also be coupled with other types of movable barriers such as gates, windows, retractable overhangs and the like. An operator is employed to control the motor and related functions with respect to the door. The operator receives command input signals—for the purpose of opening and closing the door—from a wireless remote, from a wired wall station, from a keyless entry device or other similar device. It is also known to provide safety devices that are connected to the operator for the purpose of detecting an obstruction so that the operator may then take corrective action with the motor to avoid entrapment of the obstruction.
To assist in moving the garage door or movable barrier between limit positions, it is well known to use a remote radio frequency (RF) or infrared transmitter to actuate the motor and move the door in the desired direction. These remote devices allow for users to open and close garage doors without having to get out of their car. These remote devices may also be provided with additional features such as the ability to control multiple doors, lights associated with the doors, and other security features. As is well documented in the art, the remote devices and operators may be provided with encrypted codes that change after every operation cycle so as to make it virtually impossible to “steal” a code and use it a later time for illegal purposes. An operation cycle may include opening and closing of the barrier, turning on and off a light that is connected to the operator and so on.
Although remote transmitters and like devices are convenient and work well, the remote transmitters sometimes become lost, misplaced or broken. In particular, the switch mechanism of the remote device typically becomes worn after a period of time and requires replacement. Moreover, use of the remote transmitter devices require the use of batteries which also necessitate replacement after a period of time. And although it is much easier to actuate the remote transmitter than for one to get out of an automobile and manually open the door or access barrier, it is believed that the transmitter and related systems can be further improved to obtain “hands-free” operation. Although there are some systems that utilize transponders for such a purpose, these systems still require the user to place an access card or similar device in close proximity to a reader. As with remote transmitters, the access cards sometimes become lost and/or misplaced. A further drawback of these access cards is that they do not allow for programmable functions to be utilized for different operator systems and as such do not provide an adequate level of convenience.
Another type of hands-free system utilizes a transponder, carried by an automobile, that communicates with the operator. The operator periodically sends out signals to the transponder and when no return signal is received, the operator commands the door to close. Unfortunately, the door closing may be initiated with the user out of visual range of the door. This may lead to a safety problem inasmuch as the user believes that the door has closed, but where an obstruction may have caused the door to open and remain open thus allowing unauthorized access.
U.S. patent application Ser. No. 10/744,180, assigned to the assignee of the present application and incorporated herein by reference, addresses some of the shortcomings discussed above. However, the disclosed system does not provide specific auto-open and auto-close functionality in association with the vehicle's operational status. And the disclosed system does not provide for user-changeable sensitivity adjustments. Implementing a hands-free system that has universal settings for all home installations is extremely difficult. If one designs for optimum RF range, then the opening range of the barrier is improved, but in contrast, the closing range ends up being too high. If one does not design for optimum RF range then in worst case home installations, the opening RF range might not be sufficient. In other words, if the RF signal is too strong, the barrier opens at a distance relatively far away, but closes only out of sight of the user. Or, if the RF signal is too weak, then the user must wait for the barrier to open before entering the garage. Situations may also arise where a designated sensitivity level causes the operator to toggle between opening and closing cycles before completion of a desired cycle. Other patents teach other types of transponder systems.
U.S. Pat. No. 6,616,034 to Wu, et al. discloses an identification system for tracking wafer carriers within a manufacturing facility. The system uses smart card technology in which an identification card is placed on each wafer carrier. The smart cards have memory for storing information about the wafer carrier. Power is transmitted to the card along with data so that the smart card does not require a separate power source. The devices for communicating with the smart cards can be stationary or they can be portable hand-carried devices. A network connects the readers to a central database.
U.S. Pat. No. 6,593,845 to Friedman, et al. discloses an active RF transponder that is provided with a wake-up circuit that wakes the RF transponder from a sleep state upon detection of an RF interrogating signal. The active RF transponder includes a battery, an antenna adapted to receive RF signals from an interrogator, and electronic circuitry providing the various RF transponder functions of sending/receiving signals and storing data. A first embodiment of the invention includes a wake-up circuit that periodically checks for the presence of an RF signal at the antenna. The wake-up circuit is coupled to the antenna and includes a switch adapted to selectively couple the battery to the electronic circuitry and provide electrical power thereto upon detection of the RF signals by the antenna. The wake-up circuit further comprises an oscillator providing a clock signal having a low duty cycle that defines intervals during which the antenna is sampled for presence of the RF signals (e.g., approximately 20 nanoseconds every 100 microseconds). A second embodiment of the RF transponder includes a wake-up circuit as in the first embodiment that is further adapted to detect a code sequence modulated in the RF signals. The code sequence is unique for a class of RF transponder, so the wake-up circuit can discriminate between interrogating signals. A third embodiment of the RF transponder includes a wake-up circuit that wakes the RF transponder upon detection of an RF signal that contains data within a desired band of frequencies. This embodiment enables the RF transponder to discriminate between RF signals that likely contain valid data and other RF noise. After the RF transponder has been awakened, the wake-up circuit returns the RF transponder to a sleep state if valid data is not detected within a predetermined period of time. Unfortunately, these embodiments are not connectable to an ignition system of the vehicle without an additional transmitter and receiver to inform the transponder of the ignition status.
U.S. Pat. No. 6,535,143 to Miyamoto, et al. discloses a transponder that is selectively mounted on a vehicle. The transponder receives its operational energy through magnetic coupling with a ground loop coil when the vehicle comes over the loop coil, and transmits predetermined information specific to the vehicle to the vehicle detection circuit. The vehicle detection circuit determines from the information received from the transponder whether the detected vehicle is a predetermined vehicle. This system was also found lacking in that no input is receivable from the ignition.
U.S. Pat. No. 6,512,466 to Flick discloses a vehicle tracking unit that preferably includes a vehicle position determining device, a wireless communications device, a back-up battery, and a controller connected to the wireless communications device and the vehicle position determining device. The vehicle position determining device, wireless communications device and controller define a power load of the vehicle tracking unit. The controller may isolate the back-up battery from the power load as a voltage of the vehicle battery drops until reaching a threshold. After reaching the threshold, the controller causes the back-up battery to selectively power only a first portion of the power load while a second portion of the power load remains powered by the vehicle battery. The selectively powered portion from the back-up battery may be the wireless communications device, for example, which may have a higher operating voltage. The disclosed device is effective in tracking entities such as vehicles, but it does not provide an adequate teaching in regard to the status of the ignition or the vehicle's battery.
U.S. Pat. No. 6,429,768 to Flick discloses a vehicle control system which includes a radio transponder to be carried by a user, and a radio transponder reader at the vehicle for generating control signals to enable at least one vehicle function based upon receiving a desired radio signal from the radio transponder when positioned in proximity to the reader. A jammer radio transmitter at the vehicle selectively prevents the radio transponder reader from receiving the desired radio signal from the radio transponder based upon a controller, such as an alarm controller of a vehicle security system, especially an after-market security system. The controller preferably includes a receiver for receiving remotely generated signals to operate the jammer radio transmitter. The control system may also include a remote transmitter for generating control signals to be received by the receiver. For example, the remote transmitter may be a portable transmitter carried by the user, or may be a satellite, cellular or paging transmitter remote from the vehicle. A vehicle anti-hijack switch may control the transponder jammer. The at least one vehicle function may be operation of a vehicle engine or control of the vehicle door locks. However, this is a costly approach to activate the transponder and the system does not adequately address transponder sensitivity issues.
U.S. Pat. No. 6,285,931 to Hattori, et al. discloses a vehicle diagnosis information communication system, wherein electric power is supplied from a battery to a vehicle control computer mounted on the vehicle during a period of vehicle operation, while the electric power is supplied to a radio communication unit mounted on the vehicle irrespective of the vehicle operation. The computer transmits vehicle information such as engine diagnosis results to the radio communication unit through a communication line. The radio communication unit communicates the received vehicle information to an external site of communication in response to a request of the information from the external site of communication irrespective of the supply of the electric power to the computer. Preferably, the supply of the electric power from the battery to the computer is maintained for a predetermined period after the vehicle operation.
U.S. Pat. No. 6,229,988 to Stapefeld, et al. discloses a signal receiving apparatus as, for example, that used in the monitoring a stolen vehicle transceiver for the presence of sequential transmitted signals specifically requesting that transceiver to respond to enable tracking of the vehicle. The receiver is powered by a consumable energy source of predetermined budgeted lifetime and adapted to operate between quiescent energy-saving and energized energy-consuming states for performing various functions. A method and apparatus is disclosed for insuring the availability of energy to be able to perform such functions within said predetermined budgeted life time. The method includes steps allocating budget time intervals for periodically operating the receiver intermittently in an energized state to enable the performing of such functions as monitoring for such signals; and, in the event of inordinate energy consumption during such operation, that, if continued, would render the operation out of overall allocated time budget. The method also includes adaptively skipping time intervals with the receiver quiescent, sufficiently to get the operation back on overall time budget.
Therefore, there is a need in the art for a system that automatically moves access barriers depending upon the direction of travel of a device carrying a proximity device such as a transponder. And there is a need for the system to also consider the operational status of the device and which provides for a user-changeable sensitivity adjustment for the proximity device.